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Utility routines: CopySmallBlock

[NES version, Bank 7]

Name: CopySmallBlock [Show more] Type: Subroutine Category: Utility routines Summary: An unused routine that copies a small number of pages in memory
Context: See this subroutine in context in the source code References: No direct references to this subroutine in this source file

Arguments: V(1 0) Source address SC(1 0) Destination address X Number of pages of memory to copy
.CopySmallBlock LDY #0 ; Set an index counter in Y .cops1 LDA (V),Y ; Copy the Y-th byte from V(1 0) to SC(1 0) STA (SC),Y DEY ; Decrement the index counter BNE cops1 ; Loop back until we have copied a whole page of bytes INC V+1 ; Increment the high bytes of V(1 0) and SC(1 0) to INC SC+1 ; point to the next page in memory DEX ; Decrement the page counter BNE cops1 ; Loop back until we have copied X pages of memory RTS ; Return from the subroutine